Non-linear and non-stationary resting state functional connectivity examined using fast (sub-second) functional MRI.

Abstract

Event Abstract Back to Event Non-linear and non-stationary resting state functional connectivity examined using fast (sub-second) functional MRI. Bryan Paton1, 2, 3, 4*, Parnesh Raniga1, 5 and Gary Egan1, 2 1 Monash University, Monash Biomedical Imaging, Australia 2 Monash University, School of Psychology & Psychiatry, Australia 3 Monash University, Philosophy & Cognition Lab, SOPHIS, Australia 4 Monash University, tLab, Australia 5 The Australian e-Health Research Centre-BioMedIA, CSIRO Preventative Health National Research Flagship ICTC, Australia Background: Functional connectivity (FC) analyses of functional MRI resting state data has revealed a robust set of spatial networks of intrinsic neural activity. Echo planar imaging (EPI), the primary sequence for acquiring fMRI data, has a limited whole brain imaging temporal resolution of 2-3 seconds that limits the investigation of network dynamics. Recent fast EPI sequences that decrease the minimum EPI scanning time to less than one second include the MREG and Multiband EPI sequences. Accelerated whole brain fMRI, up to ten times the temporal resolution of standard EPI, permits dynamic network analyses not previously possible. Our aim was to examine non-linear and non-stationary resting state functional connectivity using fast EPI methods and compare them to typical unaccelerated EPI data. Method: Whole brain fMRI resting state data using was collected (TR: 650 ms, TE: 30 ms, Flip Angle: 30°, 44 slices, 64 x 64 matrix, 3mm isotropic voxels, Multiband acceleration: x4) from healthy controls using the Human Connectome Project Multiband EPI sequence. We compared a number of correlational measures including cross-correlation, Kullback–Leibler divergence and sample-entropy based statistics with and without windowing. Graph theoretical network measures were derived from the resulting FC matrices. Results: Contrary to typical resting state analyses, FC derived from Multiband EPI sequences shows changes in state and configuration over both short (less than 20 s) and long (greater than 60 s) time scales. The results highlight that the assumptions of stationarity and linearity for both task related and resting state analyses are violated using fast EPI methods. Discussion: Fast EPI sequences are now available for the investigation of resting state and task-related FC applications in cognitive neuroscience. Whilst assuming that resting state data are stationary, linear and phase consistent as is the case with cross-correlation based functional connectivity, the results of fast EPI methods reveal a deeper and richer non-linear, non-stationary structure. The temporal sampling resolution now achievable using fast EPI enables novel studies investigating the dynamics of resting state and potentially task related cognitive processes. Keywords: multiband epi, functional connectivity, fMRI, non-linear, Non-stationary Conference: ACNS-2013 Australasian Cognitive Neuroscience Society Conference, Clayton, Melbourne, Australia, 28 Nov - 1 Dec, 2013. Presentation Type: Poster Topic: Other Citation: Paton B, Raniga P and Egan G (2013). Non-linear and non-stationary resting state functional connectivity examined using fast (sub-second) functional MRI.. Conference Abstract: ACNS-2013 Australasian Cognitive Neuroscience Society Conference. doi: 10.3389/conf.fnhum.2013.212.00056 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 15 Oct 2013; Published Online: 25 Nov 2013. * Correspondence: Mr. Bryan Paton, Monash University, Monash Biomedical Imaging, Clayton, VIC, 3168, Australia, bryan.paton@newcastle.edu.au Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Bryan Paton Parnesh Raniga Gary Egan Google Bryan Paton Parnesh Raniga Gary Egan Google Scholar Bryan Paton Parnesh Raniga Gary Egan PubMed Bryan Paton Parnesh Raniga Gary Egan Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.